Wrench



J. E. BERGMAN.

WRENCH. APPLICATION H'LEp MAY 8,1919.

Patented May 17,1921.

I UNITED-1 STATES PATENT OFFICE.

JEROME. EBERGMAN; OF IBIIEEALQ, NEW

WRENCH.

To' all whom it may concern:

Be itknown that; I, J nRoMn E. BERGMAN,

a citizen of the United States, residing atv Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Wrenches, of which the following is a specification.

This invention wrenches having a movable jaw which is adjusted toward and from the fixed jaw by a Worm or equivalent rotary member, and an automatic lock or detent device for the worm which 'checks its rotation and prevents accidental displacement of the movable jaw.

One object of my invention is the provision of a neat and inexpensive detent device of this character which acts frictionally to resist rotation of the worm, thus reliably locking the movable jaw and at the same time permitting the worm to be turned with little effort in adjusting the wrench to a nut or other part and without the necessity of manipulating the detent device.

In the accompanying drawings: Figure 1 is a side elevation of a wrench embodying the invention. Fig. 2 is a sectional elevation of the head of the wrench. Fig. 3 is a transverse section on line 38, Fig. 1. Fig. 4 is a perspective view of the detent spring, showing its original form.

Similar characters of reference indicate corresponding parts in the several views.

The head 10 of the wrench has the usual handle 11 and carries the fixed jaw 12 which is preferably integral therewith.

13 indicates the movable jaw which is guided in the head and adjusted relatively to the fixed jaw by a rotary adjusting device of any suitable construction. In the preferred construction shown in the drawings, the movable jaw is provided at its base with a toothed rack 14 which is engaged by the customary knurled worm 15. The latter is arranged in a transverse opening 16 in the wrench-head and journaled on a screw or in 17 secured in the head. This rack and the shank 18 of the movable jaw slide in the usual undercut slot 19 of the head.

Bearing against the side of the adjusting worm, preferably its underside, is a frictional detent device 20 of any suitable con struction. In its preferred form, this device consists of a bifurcated or U-shaped spring which straddles the web belongs to the class of or part 21 of the, head forming the lower edge of the opening Specification of Letters Patent. P atente flMay 17, 192 1- Application filed. Mayv 8', 1919. Serial No. 295,604."

16 and bears against the worm with" sufficient force to prevent involuntary rotation there of. For-thispurpose, the: web 21 istapered upwardly, I front and rear sides, and the legs 20'of the detent spring bear against said sides. In its normal condition before being applied to the wrench, the legs of the spring are substantially parallel, as shown in Fig. 4, and are so spaced that they must be spread or sprung over the beveled web, as shown in Fig. 3, with the result that the legs tend to contract and ride up on the beveled faces of the web, thus constantly pressing the top or web 20 of the spring against the underside of the worm.

This detent device, while holding the worm from turning with the necessary force to maintain the movable jaw in the desired position, permits the worm to be turned with comparatively little effort to change the adjustment. The necessity for repeatedly readjusting the wrench is thus avoided rendering the tool more convenient in use and enabling a nut or other part to be tightened or loosened in much less time.

The frictional character of the detent device also facilitates the adjustment, since it does not require manual release of the detent device which is necessary in wrenches where a positive lockingengagement takes place between the worm and the detent device.

The device, moreover, is neat in appearance, and its construction is exceedingly simple, enabling it to be manufactured at small cost. The improvement has the fur ther advantage of requiring no material departure from the conventional form and construction of wrenches of this type.

The invention is obviously applicable to various forms of wrenches having a rotary adjusting member for the movable jaw, and I do not therefore wish to be limited to the particular embodiment herein shown and described and this applies also tothe details of construction which may be modified within the scope of the appended claims without departing from the spirit of the invenhaving a beveled surface, and a resilient frictional detent engaging said beveled sur face and bearing constantly against said adjusting member. H v

2. A wrench, comprising a head carrying a fixed jaw, a movable jaw, a rotary adjusting member for the movable jaw, said head having a part beveled on opposite sides, and a bifurcated spring-detent straddling said beveled part and bearing against said adjusting member.

3. -A wrench, comprising a head carrying" a fixed jaw, a movable jaw, a rotary adjusting-member for the movable aw, sald head having a member which tapers toward the side of said adjusting member, and an approximately U-shaped spring straddling said tapering member and bearing against said adjusting member.

4. A wrench, comprising a head carrying a fixed jaw, a movable jaw, said head having an opening below the movable jaw, a rotary adjusting worm for the movable jaw arranged in said opening, the lower edge of said opening having beveled sides converging toward the worm, and an approximately.

U-shaped detent spring straddling said bev eled edge and bearing a ainst said worm.

1 JERO E. BERGMAN. 

